Dry aging creates a unique taste and flavor in beef; however, the process also causes rancidity, which is harmful to humans. During dry aging, the microbial flora in beef changes continuously; thus, this change can be used as an indicator of rancidity. The objective of this study was to analyze the correlation between microbial flora in beef and rancidity during dry aging. The round of beef (2.5–3 kg) was dry aged under 1.5 ± 1 °C and 82 ± 5% moisture for 17 weeks. The microflora in the dry aged beef was analyzed by pyrosequencing. The volatile basic nitrogen (VBN) and thiobarbituric acid reactive substance (TBARS) values were also measured. Primers were designed to detect and quantify bacteria using real-time polymerase chain reaction (RT-PCR). The VBN and TBARS values in the dry aged beef depreciated from week 11 of aging. The levels of Streptococcus spp., Pantoea spp., and Pseudomonas spp. significantly changed at around week 11. Quantitative RT-PCR showed that the levels of Pantoea spp. and Streptococcus spp. could be used to identify rancidity during dry aging. Thus, among the microbial flora in dry aged beef, Pantoea spp. and Streptococcus spp. can be used to determine the rancidity of dry aged beef.
Plant extracts have been used as herbal medicines to treat a wide variety of human diseases. We used response surface methodology (RSM) to optimize theArtemisia capillarisThunb. extraction parameters (extraction temperature, extraction time, and ethanol concentration) for obtaining an extract with high anti-inflammatory activity at the cellular level. The optimum ranges for the extraction parameters were predicted by superimposing 4-dimensional response surface plots of the lipopolysaccharide- (LPS-) induced PGE2and NO production and by cytotoxicity ofA. capillarisThunb. extracts. The ranges of extraction conditions used for determining the optimal conditions were extraction temperatures of 57–65°C, ethanol concentrations of 45–57%, and extraction times of 5.5–6.8 h. On the basis of the results, a model with a central composite design was considered to be accurate and reliable for predicting the anti-inflammation activity of extracts at the cellular level. These approaches can provide a logical starting point for developing novel anti-inflammatory substances from natural products and will be helpful for the full utilization ofA. capillarisThunb. The crude extract obtained can be used in someA. capillarisThunb.-related health care products.
31 December 2019 in Food Science of Animal Resources
Food Science of Animal Resources (Food Sci. Anim. Resour.) is an international, peer-reviewed bimonthly journal publishing original research and reviews on basic and applied aspects of the use of animal resources including the meat, egg, and dairy product. Food Sci. Anim. Resour. is published and distributed by the Korean Society for Food Science of Animal Resources.
28 February 2013 in Food Science and Biotechnology
A simultaneous analytical method for piperine, capsaicin, and dihydrocapsaicin in Korean instant-noodle soup base using HPLC was validated in terms of precision, accuracy, sensitivity, and linearity. The HPLC separation was performed on a reversed-phase C18 column (5 μm particle size, 4.6 mm id, 250 mm length) using a UV detector fixed at 280 nm. The LOD and LOQ of the HPLC analyses ranged from 0.25 to 1.03 mg/kg. The intraday and interday precisions of the individual piperine, capsaicin, and dihydrocapsaicin were <10.55%, and the recovery values ranged from 85.43 to 94.68%. The calibration curves exhibited good linearity (r2 = 0.999) within the tested ranges. These results suggest that the analytical method in this study can be used to classify Korean instant noodles based on their levels of spiciness.